Polarized source upgrade Time meeting June 4 Source

Polarized source upgrade. Time meeting, June 4 Source upgrade project -2010 -12. Main component delivery: Atomic Beam Source- August 2011 Superconducting solenoid- March-2012 The development is not completed, but the new source delivers better quality beam in this Run-13.

Operational Polarized H- Source at RHIC OPPIS produces reliably 0. 5 -1. 0 m. A polarized H- ion current. Polarization at 200 Me. V: P = 80%. Beam intensity (ion/pulse) routine operation: Source - 1012 H-/pulse Linac - 5∙ 1011 AGS - 1. 5 -2. 0 ∙ 1011 RHIC - 1. 5∙ 1011 (protons/bunch). A 29. 2 GHz ECR-type source is used for primary proton beam generation. The source was originally developed for dc operation. A ten-fold intensity increase was demonstrated in a pulsed operation by using a very high-brightness Fast Atomic Beam Source instead of the ECR proton source.

Pulsed OPPIS with the atomic hydrogen injector at INR, Moscow, 1982 -1990. Atomic H injector Helium ionizer cell ~80% ionization efficiency. H- current 0. 4 m. A, P=65% Lamb-shift polarimeter

OPPIS with atomic H injector layout. CP 1 TMP 1 Neutralizer cell Atomic H injector H+ H 2 He-ionizer cell H 0 He Na-jet cell Rb-cell H+ Rb H 0 Na H-

A result of this “upgrade” is practically a new source. • • • A new superconducting solenoid. A new atomic hydrogen injector. A new vacuum system. A new H-ionizer cell, energy separation system and pulsed PS system. A new control and interlock system. Major upgrades of laser system. Major modifications of the Low Energy Beam Transport system. Major upgrades in 200 Me. V polarimeter. A new test-bench for atomic injector studies. Many other upgrades…

“Fast Atomic Beam Source”, BINP 2011 Plasmatron 4 -grid proton extraction system ~ 3. 5 A equivalent H 0 beam H 2 Neutralization cell FABS produces 200 -300 m. A equivalent H 0 beam intensity Within the Na-jet ionizer acceptance.

He-ionizer cell and three-grid energy separation system. He-pulsed valve 3 -grid beam deceleration system

New PLC interlock and monitoring system. Graphics by Yuri Bezpalko

Source intensity and polarization. • Reliable long-term ∙operation of the source was demonstrated. • Very high suppression of un-polarized beam component was demonstrated. • Small beam emittance (after collimation for energy separation) and high transmission to 200 Me. V. Rb-cell, Temp. , deg. C 81 Linac Current, μA 295 86 370 91 410 96 570 Booster Input × 1011 4. 9 6. 2 7. 3 9. 0 Pol. %, at 200 Me. V 83 -84 83 80. 5 78

Rb-81, T 9 -current-295 u. A (4. 9*10^11) 84. 2+/-0. 5% 83. 9+/0. 9%

Polarization measurements at 200 Me. V, March 1 -4 83%

200 Me. V polarization in Run-2012, high intensity operation 80%

Summary • The new source is working. Reliable long-term operation at steady current and polarization. • The maintenance time is significantly reduced. • Polarization is on average about 3% higher then ECR-based source. It is expected that polarization can be further improved to over 85%. • The source intensity is about 5 -10 m. A. Due to strong spacecharge effects only fraction of this current is transported and accelerated in RFQ and Linac. These losses can be reduced.